摘要

Four types of high speed electrical multi units (EMUs) have been operated since April of 2007 in China and the top velocity of two of them reached to 350 km/h in 2008. By use of a reliable test technology, the axle spring forces of the high speed EMU are tested on the Beijing-Tianjin railway line to obtain the dynamic characteristics of the primary vertical suspension loads. The test data for 10 days covers 11000 km railway line approximately. The axle spring loads on some typical operation conditions such as high speed running, turnout passing, negotiating, station passing and returning to EMU depot are sampled to represent its dynamic levels and load frequencies. The load spectrums of the axle spring for two days are presented to obtain the relationship between the load times and the running distance. It is shown that the track excitation has great influence on the dynamic loads and the vibration of the motors and gear boxes has effect on the spring loads too. The maximal dynamic coefficient of the loads is about 0.38 and the maximal loads generally appear on the depot entrance and connects sections. The natural frequencies of the EMUs are 1.S1 Hz and 11 Hz which are excited by the track excitation on the straight railway division. The research results can be used to guide the bogie structural design, service life assessment, and related theoretical study.